A variety of different materials reducing machines and apparatuses are known in the art which receive large bulky materials, e.g., logs, tree stumps, brush, yard waste, pallets as well as other materials, and process the same for recycling or disposal, for example. Typically a large rotor, containing a plurality of replaceable blades, knives, teeth, hammers or strikers on a peripheral surface thereof, is rotated at relatively high speed so as to strike the incoming material in either a downward or an upwardly arcing path and produce a shearing action of the material to be reduced which assists with conversion of material into smaller pieces which are more convenient for subsequent disposal, handling, recycling, etc.
A feed conveyor is generally provided for feeding material into the downward or the upwardly rotating rotor. A screen generally surrounds a major periphery of the rotating arc of the rotor to assist with the conversion of the large pieces of material into particles of a desired smaller size for subsequent handling and recycling.
A prevalent problem associated with prior art material reducing apparatus is that metal, or some other hard material, tends to be intermixed with the debris, logs, tree stumps, brush, yard waste, pallets or other material to be recycled. If any hard material is attempted to be reduced by the material reducing apparatus, this normally causes the anvil(s), the hammer(s), the striker(s) and/or other internal components within the material reducing apparatus to be dented, chip, fracture and/or break. Prior art attempts to compensate for this have been to provide shear arrangements which allow one or more components to be pivotally supported by shear pins and break away when a hard material is attempted to be reduced by the material reducing apparatus. The problem with such shear arrangements is that, although they are somewhat effective in minimizing damage to the material reducing apparatus, they still result in some damage occurring to the material reducing apparatus which, in turn, leads to costly down time while the material reducing apparatus is shut down so that the chipped, fractured or broken part(s) can be repaired or replaced.